Work from fluctuations

  Asymmetry: Can asymmetry and ratchet forces be used to extract energy from fluctuations?

This is clearly not possible in thermal equilibrium (time reversal symmetry).

Non-equilibrium fluctuations can indeed generate force and motion

• Random motion of bacteria:                                   
• Whether any form of "active matter" leads to ratchet motion is ongoing activity.
• Feynman's ratchet and pawl:  (youtube)                

 Nonequilibrium fluctuations + asymmetry can potentially lead to motive force

 Radiative heat transfer as source of nonequilibrium fluctuations

Next (Heat) Outline Casimir force Work extraction Fluctuational QED Engine Summary